1. Field of the Invention
The invention relates to a process for the preparation of cyclooctanol by reaction of cyclooctene with formic acid to give cyclooctyl formate, phase separation after the reaction into a lower A phase rich in formic acid (formic acid content &gt;60%) and an upper B phase low in formic acid (formic acid content &lt;20%), extraction of cyclooctyl formate from the A phase, combination of this extract with the B phase, gentle distillative work-up of the reaction mixture which contains the cyclooctyl formate via a short distillation path, and transesterification of the cyclooctyl formate to give cyclooctanol.
2. Discussion of the Background
Cyclooctanol is an important intermediate for the preparation of, inter alia, cyclooctanone, which is required in the pharmaceutical sector, and for the preparation of fragrances. Syntheses of cyclooctanol from cyclooctene via the formate are known from the literature. For example, GB 1 153 468 describes a process in which formic acid is added to cyclooctene without catalyst, the reaction mixture is worked up distillatively and the cyclooctyl formate thus obtained is hydrolyzed with sodium hydroxide solution. It is pointed out that the temperatures during the distillation must be very low. In order to avoid decompositions, temperatures of less than 100.degree. C. are required. However, in the case of industrial implementation, this requirement cannot be realized and, even in Example 1, a temperature above 100.degree. C. is given as the boiling point of the formate. The relatively poor yield of only 82% based on reacted cyclooctene is attributable to thermal decomposition. A further disadvantage of this process is that the hydrolysis of the formate using sodium hydroxide solution produces at least stoichiometric amounts of sodium formate, which have to be disposed of.
The object of the invention was therefore to find a process which is easy to carry out industrially and in which such thermal decomposition does not take place and in which no noteworthy amounts of salts are produced as waste material.